How Should a Processing Plant Be Built for Alluvial Gold Deposits with Thick Alluvial Layers? EPC Turnkey Solution for a Complete Gravity Separation Production Line

1. Ore Washing and Classification: The Core Step for Thick Alluvial Deposits

The clay content in thick alluvial deposits varies with depth, so ore washing must be thorough and allow for flexibility in adjustment. Cylindrical ore washers or trommel screens combine washing and screening functions; high-pressure water flushing, combined with the rotation of the cylinder, breaks up clay clumps.For mining sections with high clay content, a two-stage configuration is recommended: preliminary washing with a spiral washer followed by secondary washing with a trommel screen. The pressure and flow rate of the wash water can be adjusted according to the clay content to prevent downstream chute blockages and gold loss in the centrifuge caused by inadequate cleaning by a single piece of equipment.

Screen aperture size is determined based on gold particle size and the requirements of subsequent equipment; typically, the material is classified into coarse and fine fractions, which are fed into different gravity separation devices.

2. Chute Roughing: Capturing Coarse Gold Particles

The slurry from the undersize of the ore washer enters the sluice boxes. Sluice boxes feature a simple structure, high throughput, and low cost, making them suitable as roughing and concentration equipment.For gold-bearing sand deposits in thick alluvial layers, which have high processing capacities, the chute configuration must ensure sufficient length, slope, and the number of parallel units; gold-trapping mats or agitated chutes should be selected based on slurry concentration. Concentrates from the chutes are periodically cleaned out and sent to centrifugal separators or shaking tables for further enrichment.

3. Enrichment Using a Centrifugal Separator: The Key to Recovering Fine-Grained Gold

The proportion of fine-grained gold in thick alluvial deposits is significant, and sluices have limited recovery capacity for this fraction.Centrifugal separators enhance gravity separation based on the principle of centrifugation, achieving significant enrichment of ultrafine gold particles; they are the core equipment for recovering fine-grained gold from placer gold deposits. Feed particle size, centrifugal force, and backwash water pressure must be adjusted according to the properties of the ore.

4. Shaking Table Refining: Producing Qualified Concentrate

The concentrate from the centrifuge and the chute are combined and fed to the shaking table for final selection. 6-S shaking tables or multi-deck suspended shaking tables offer high separation precision, enabling further separation of heavy minerals from light gangue to produce gold concentrate suitable for direct smelting.Shaking table operating parameters (stroke, stroke rate, transverse slope, and feed concentration) directly affect concentrate grade and must be calibrated on-site during the commissioning phase.

5. Smelting: Production of Alloyed Gold

After drying and blending, the concentrate is fed into a gold smelting furnace to produce bulk gold ingots. As the concentrate may contain associated heavy minerals such as magnetite and ilmenite, magnetic separation to remove iron or acid leaching pretreatment may be performed prior to smelting, depending on the circumstances.

What GoldProcessingPlant Is Responsible For

1. Process Design and Technical Solutions: Analysis of ore sample characteristics, determination of processing flows, equipment selection, and preparation of proposal documents with preliminary quotations.
2. Engineering Design and Drawings: Core design drawings such as site layout plans, equipment layout diagrams, and civil engineering condition drawings, along with a complete technical briefing.
3. Manufacturing of Core Equipment and Supply of Supporting Components: Manufacturing core equipment—such as trommel screens, ore washers, chutes, centrifugal concentrators, shaking tables, and sand pumps—in accordance with drawings; coordinating the supply of auxiliary materials, including pumps, piping, and electrical controls, to ensure seamless integration between hardware and process.
4. On-Site Installation Technical Guidance: Dispatch engineers to the site to supervise equipment positioning, pipeline connections, and electrical and instrumentation installation, ensuring that construction crews follow the drawings precisely.
5. Integrated Commissioning and Personnel Training: Lead the commissioning of individual units and full-process integrated trial runs with water and feed material; optimize parameters such as feed concentration, rinse water pressure, centrifuge backwash water, and shaking table inclination until standards are met and full production capacity is achieved; provide theoretical and hands-on training to the client\'s team.
6. After-Sales Service and Spare Parts Supply: We assume responsibility for equipment quality during the warranty period and provide long-term spare parts supply and process optimization recommendations.

Client Responsibilities

1. Civil Engineering Construction: The client shall independently organize civil engineering construction in accordance with the civil engineering specifications provided by us (equipment foundations, loads, reserved openings, water and electricity connections, etc.). If complete architectural construction drawings involving plant structures, foundation reinforcement, etc., are required, these must be issued by a qualified local design institute.
2. Organization of Local Installation Workers: Specific installation tasks—such as equipment positioning, pipe welding, and cable laying—must be carried out by workers recruited locally by the customer. Our engineers will provide on-site guidance on installation procedures, while the customer is responsible for organizing the workforce to perform the work.
3. On-site Infrastructure: The client is responsible for ensuring the site is “connected to water, electricity, and roads, and leveled” (three utilities and site leveling), as well as for preparing the water, electricity, and materials required for equipment hoisting and commissioning.
4. Local Compliance Procedures: The client is responsible for obtaining local approvals, including environmental protection, safety, and construction permits, at the project site.

Process-First Approach, No One-Size-Fits-All Templates

Thick alluvial deposits differ from colluvial, residual, and riverbed deposits in terms of clay content and grain size distribution; therefore, process parameters should not be the same. GoldProcessingPlant has over 20 years of experience in gold ore beneficiation process design and equipment manufacturing, with proven solutions for the entire process—from placer gold washing and gravity separation to refining.

In-House Equipment Manufacturing: Process and Hardware Seamlessly Integrated

We independently manufacture the full range of equipment for the placer gold gravity separation process—including trommel screens, ore washers, chutes, centrifugal separators, shaking tables, and sand pumps. Process engineers and mechanical engineers collaborate as a single team, ensuring equipment is manufactured according to process drawings to avoid discrepancies such as “design drawings not matching equipment dimensions.”With two major manufacturing bases covering approximately 50,000 square meters and an annual production capacity exceeding 500 units, our products are exported to more than 50 countries and regions. We strictly adhere to the ISO 9001 quality management system, and our products are CE certified.

Unbroken EPC Responsibility Chain

We provide comprehensive coordination of process design, equipment manufacturing, installation guidance, integrated commissioning, and personnel training, and take full responsibility for the final production targets. We do not shift blame to design institutes, equipment manufacturers, or construction teams when issues arise.

Global Project Experience

Projects span major gold-producing regions including Ghana, Mali, and Tanzania in Africa; Peru and Colombia in South America; Russia and Kazakhstan in Central Asia; and Southeast Asia, with processing capacities ranging from 30 to 5,000 metric tons per day. We are well-versed in international logistics, customs clearance procedures, and construction standards across different countries.In Africa, where power supply is unstable, we provide diesel generator sets; to address transportation difficulties during the rainy season, we stock up in advance; and when local workers have limited technical skills, we provide hands-on training.

Flexible Phased Implementation, No Mandatory Bundling

Clients may choose to conduct only mineral processing tests, purchase only process design and equipment selection plans, procure only equipment, or hire engineers for on-site commissioning; alternatively, they may opt for full-process EPC. Upfront payments for mineral processing tests and design fees can be fully offset against equipment costs when subsequent equipment or EPC contracts are signed.

Ongoing Technical Support

Commissioning and reaching full production capacity are just the beginning of our partnership. We assume responsibility for equipment quality during the warranty period and, after the warranty expires, continue to supply spare parts, provide technical consultation, and offer process optimization recommendations on an ongoing basis. As the grade and silt content of thick alluvial deposits vary across different mining sections, recovery parameters must be adjusted accordingly—and we\'ll be there every step of the way.